Abstract:

In view of the abnormal phenomenon of test conclusion in the performance evaluation of inhibitors for drilling fluid,the adaptability of the evaluation methods for the inhibition of various inhibitors,including inorganic salts,silicate,polyvinylalcohol,etc.,is discussed through the shale linear swelling test,core soaking test,heat rolling recovery test,core drop dye scanning electron microscope test and other methods.The results show that KCl and NaCl with low concentration are not suitable to be evaluated by artificial core immersion test and linear swelling test.The linear swelling test requires inhibitor concentration above 0.3% and test time no less than 6 h.The viscosity of the base slurry has an obvious effect on the hot roll-ing recovery rate.The higher the viscosity of the base slurry leads to the higher the initial recovery rate.Therefore,more attention should be paid to the influence of evaluation methods,inhibitor concentration,test time,base slurry viscosity and other factors for evaluating the effect of inhibitors in order to seek targeted evaluation methods to avoid getting wrong test conclusions.

Key words: shale, inhibitor, inhibition evaluation, linear swelling test, shale hot rolling recovery test